Bearing



Nm?. 115, T927. 1,649,285

' -T. v. BUCKWALTER BEARING Filed June 4, 1924 ls sheets-sheet 1 Y'nde/inzon- Nov. 15,1927.

q T. v. BUcKwALTER BEARING Filed June 4, 1924 5 Sheets-Sheet 2| Jorney,

Patented Nov. 15, 1927. l

UNITED 'STATES PATENT orifice.t

TRACY Av. BUCKWALTER, or

- COMPANY, or

CAN'ION, OHIO, ASSIGNOR TO TIMKEN ROLLER BEARING CANTON, OHIO, ACORPORATION OE OHIO.

BEARING. l

Application filed .Tune 4,

`-cured by making the thrust-transmltting roller surfaces, preferably onthe outer and vlarger ends of the rollers, of such contours as tocoincide (either entirely or at a plurality of points) with sections ofspherical contours generated about acenter coincident With the point ofintersection of the projected axes of rotation of the rollers and theaxis` of rotation of the bearing or the projection-thereof; thespherical contours or surfaces respectively having radii equal to o1approximating the distance between such point of intersection and apoint/ on the thrust-transmitting surfaces of the respective rollers. Athrust-resisting/and guiding surface having a contour conforming withthe'thrust-transmitting surfaces of the rollers is formed upon one orboth of the races with which the rollers cooperate, and preferably therollers are sotapered that the vvertices of their generating elementscoin- -eide With the point of 4intersection above specified.

In bearings constructed in accordance with my improvements, the loadtends to force the rollers outwardly--away from the point ofintersection of their projected axes with the axisofvthe bearngs-andintoco'n tact with a pressure-resisting and guiding flange or rib. Viththe thrust-transmitting that such roller carries.

surfaces spherically curved about the center and on the radiusspecified, the entire'juxtaposed surfaces will make surface contact andthe rollers will .be given true rolling motion, Without tendency toslide or drag on the flange. Any tendency of a roller to deviate fromcorrect axial alignment results in the roller being forced inward (dueto the broad bearing on the flange ofthe roller end or bearing surfacetransverse to its axis) thereby increasing the portion ofthe total loadThe normal action of the roller Will be to slide outward from under suchexcess load, and to maintain the 1924. Serial No. 717,742.

extended surface contact at the spherical surfaces and correct. axialalignment.

It will be recognized that the radius of the spherical curvature of theroller end and of the guiding and pressure flange may, in some cases, berelatively large compared with the diameter or other dimensions of theroller. Hence for certain purposes, and for convenience inmanufacturing, the contours of the juxtaposed thrusttransmittingsurfaces may, Without substantial detriment, be

so modified as to form a surface initially coincident at. a poi-nt orpoints,.but not necessarily at all points, with a true spherical surfacegenerated as above described about 'a center coincident with the pointof intersection of the roller axes (or the vertices of the rollergenerating elements) With the axis of rotation of the bearing. Forinstance, the outer and larger end of the roller, insteadl of being aportion of a true sphere, may be formed by the rotation about the rolleraxis of a straight line element, provided the angle'of the end of theroller With respect to the working surface approximates that of thetheoretically correct spherical surface. The generating element formingsuch modified thrust-transmitting bearing surface is preferably a lineat right angles to a` radius drawn from the point of intersection abovespecified to a point in the bearing zone of a rollerhaving atheoretically correct spherical contour, hence the generating element istangent to or parallel with a tangent to the theoretically correctspherical contour at a point Within the bearing zone thereof, and formsan angle relatively to a line perpendicular to the roller axiscontaining a number of degrees not substantially differing from thenumber of degrees in the angle formed by the intersection of the are ofthe theoretically correct surface With such vperpendicular. The point oftangency of such generating element to the theoretically cor rectsurface is preferably such as to effect initial contact of the rollerend or thrust-transmitting surface With the guide rib or flange atseparated points adjacent to but not at the inner edgeof the zone ofcontact of the theoretical surface, thus giving initially twopointguidance to the'roller; but the initial contact may be 'made at or nearthe outer edge of the zone of contact of the theoreti cally correctsurface, with resulting initial single point contact: or the initialcontact l .ner and outer edges of the contact zone'of necessary a cagemay,

vting surfaces generated raceways the theoretically correct surface.'lin any case, the spot contacts may be worn down to produce a closeapproximation to the theoretically correct'spherical surface contact bycomparatively slight service relative- 'ly to the life of the bearing.

The characteristic-features and advantages of Ely-improvements will morefully appear from the following description and the accompanyingdrawings of illustrative embodiments thereof. j j

In the drawings, Fig. l is a transverse sec tional view of al thrustbearing embodying my improvements; Fig. 2 is a transversesectional viewthereof atv right angles to Fig. l; Fig. 3 is a lpartialfside elevationof`the same construction with parts broken away to illustrate thesurface contact.A obtained between the end of the roller andtherib; Fig.4 is atransverse sectional view showing a modified raceway structure;Fig. 5 is a transverse sectional view showing a further modifiedraceway'structure; Fig.l 6 is an enlarged fragmentary view illustratingthe appearance ofy a bearing with a radius formed on the edge of the riband on the edge of the roller; Fig. 7 diagrammatically illustrates thesurface contact resulting from the breaking of the edges as shown inFig. 7, the surface-within the light line being the resultant surfacecontact; Fig. 8 is a transverse sectional View illustrating theapplication of my invention to a roller bearing having 1nner and outerrace-rings and primarily adapted for carrying radial loads; Fig 9 is a.diagrammatic fragmentary sectional View of a roller bearing havingthrust transmitby straight line elements; Fig. l0 is a fragmentary viewon the line l0-10 of Fig. 9 and illustrating the initial contact pointsof the bearing surfaces; and Fig. l1 is a fragmentary view illustrat.ing the adaptation of bearing surfaces hav-l ing straight linegenerating elements from the spherical bearing surfaces of a thrustbearing.

Asillustrated in Figs..1 to 3 of the drawings, the similar race rings ordisks lfand 2, provided wth inwardly converging conical 3 and et, aresecured together by `a cylindrical peripheral jacket '5 having flanges 5engaging the shoulders l and 2 of the race-rings. Y .a

The Ispace between the raceways 3 and 4 is preferably completely filledwith conoidal rollers 6 tapering towards the axis of rotav tion of thebearings, 6.0

and having the apices of their generating elements and their axes ofrevolution converging in the axis of rotation of the bearing. Whilegenerally unif desired, be employed Cguiding the rollers.

- 4' have the same into spaceqand assist in The raceways '3 an -therollers are provided with end' .ing surfaces of the pressure `the largeconvex ends ofv the rollers.

clinations as the tapering surfaces of the rollers. i

The load upon the bearing has ai tendency to vforce the conoidal rollersoutwardly, and surfaces 7 for transmitting thrust tothe guiding andthrust-resisting flanges 8 formedon the racerings land 2;

In order to incorporate in the bearing the greatest practicable numberof rllers, itis desirable to eliminate the usual cage for separating andguiding the rollers, which necessitates the' provisionv of means formak` ing the rollers self-aligning. This desiderata is attainedefficiently by convexly curving the .thrust-transmitting surfaces of theroller ends and concavely c-urving the coactgive them' a contourcoinciding with the contour of aO spherical segment having a centercoincident with the point 9 at the intersection of the projected axes ofthe rollers, the projected generating elements of lthe rollers, theapices yof the projected conical surfaces 'of the raceways,. and theIaxis of rotation of the bearing.` .The radius of 'such spherical contour4or surface is equal to or approximatesthedistance between such pointvof intersection andthe outer end of-the roller when in normal'posi-ltion. By so shaping the rollers and ilang lthe contacting surfaces4thereof make full surface contact throughout their overlappingportions, as indicated by the cross-hatching in Fig. 3.

In the modification illustrated in Fig. 4, only one ofthe race-rings isprovided with a pressure: and guiding flange, the other racering 2abeing made conoidal but plain. This form of bearing may be desirableunder certain conditions for greater economy of production and stillprovides sufficient surface contact at the end o'f the roller to producethe desired result.

In Fig; 5 is illustrated a modification in which one of the race-rings2" comprises a substantially flat washer having a raceway 4perpendicularo to the axis of the bearing, while the raceway 3 of theother race-ring lb is sharply inclined and provided with a peripheralpressure and guiding Aflange 8 having aconcave surface conforming withThe contacting surfaces are coincident with the.

contour of a segment of a .sphere-whose center is coincident with theprojection of the working face ofthe flat race, the inclined surface ofthe conical race, the axes of the axis ofthe-.bearing The rollers andthe radius of 'the spherical .segment foreach roller is the distancebetween the point of intersection above of the roller when in'normalposition.

To avoid localization supported edges, vit vmay be desirableto form ofstrain` on poorly l' flanges 'so as to I referred to and theouter end lor rib on a radius and to form the outer edge of the roller on a radius,as illustrated at 8a and 6a in Fig. 6, With resulting surface contactbetween the roller and rib as illustrated by the section 10 Within thelight lines of Fig. 7.

As illustrated in Fig. 8, my improvements are applied to ananti-friction bearing for carrying radialloads comprising an inner coneor racc-ring 11 and an outer cup or racering 12 provided withcooperating races 13 and 14 in which conoidal rollers 15 are disposed.The rollers have convex outer ends 16 each coincident with the contouror cur-ved surface of a spherical segment generated about a center 17formed by the intersection of the apices'of the roller generating ele#ments, the axes ofrevolution of the rollers, andthe axis of rotation ofthe bearing, the radius of the spherical surface or contour for eachroller being equal to the distance between such point of intersectionand the outer. end of such roller when in normal position. `Therace-ring 11 is provided with a pressure and guiding iiange 18 having aconca've surface conforming with the' curvature' ofthe coacting surfaceof the rollers. With suchconstruction, the

fload forces the spherical outer ends 'of th'e rollers against theconcave surface of the rib 18, with which they make extended surfacecontact, resulting in the automatic axial alignment of the rollers. y

When the radius of the theoretically correct spherical curvature of theend of the roller is comparatively large relatively to the diameter ofthe roller, the spherical contour of such axial thrust transmittingsurfaces may be modified as vindicated in Figs. `9, 10 and 11 Withoutsubstantial detriment to the operation.

In Figs. ly illustrated a rollei' bearing similar to that shown in Fig.8 and comprising a race ring 11 forming a conical raceway 13in Which areseated tapered rollers 15 adapted for cooperation with an outerrace-ring (not shown). The outer ends of the -rollers 15 transmit axialthrust to the thrustresisting flange or bearing rib 18 of the race-ring11.

The axesof rotation of the rollers, the vertices of the generatingelements of the tapered longitudinal Walls of the rollers, and theapices of the conical races all meet at a point 17 in the projection ofthe axisof rotation of the roller bearing.

In accordance with the principles above enunciated, 'the ,axial-thrusttransmitting surfaces should coincide with a spherical surface havingits center at the point 17, and in the particular construction shown thearc forming the endI of the roller Would be measured by an angle of 3degrees 10 minutes. With thrust transmitting surfaces so necting theextreme points vbe-varied as desired. 9 and 10 there isdiagraminaticalformed, the -Width of the rollers and rib would be thedistance between the points A and B, the edge 18a of the 'rib -beingformed on aradius and the edge 15a of the roller being formedl on aradius, as explained in connection with Figs.

6 and 7. Since, cally correct curvature isvery large compared with thediameter' of the roll and- With the Width of thez'one of contact betweenthe theoretically correct surfaces, it is practicable toy-formsatisfactory thrust transmitting surfaces -generated by strai glit lineelen-ients tangent to the' correct surfaces. 4 y

To determine such Astraight line surfaces for the' outei-ends oftherollers, there is rotated about the rollers longitudinal axis agenera-ting element perpendic'ularto a radius D drawn from the point 17to a point in the contacting zone bet-Ween the points A-B of a surfaceof theoretically contour. 'As illustrated, the outer end oi'l suchradius falls slightly Within the border the contacting zone ofv however,the radius ofthe theoreticorrect of the zone, and the generating elementis l the theoretically cortherefore tangent to hence rect curved surfaceat the point D;

the initial points ofactual Contact of the such projection with thelines A-B conbearing zones formed on a theoretically coi',- rectcurvature.

of contact of I making the generating'elenient form@v ing the bearingzone a perpendicular to other .radii between points of'tangency and hence of initial conL tact of the thrust transmitting surfaces 'can Itis, however, desirable to have these initial contact points separated asfar as possible without having initial contacts made at-the extreme edgeol' the theoretical zone of'contact between the roll and rib.

In the particular construction shown by Way of example in Figs. 9 and10, the gen-c erating element 'perpendicular to thejradius D makes anangle of 89 degrees 35minutes With the generating element of the taperedlongitudinal Wall of the roller and makes-an angle of 88 degrees 5()minutes With the axisof rotation of the roller, hence the angularity'ofthe roller end relatively to a plane the roller axis is 1 degree atright angles to 10 minutes.

The thrust resisting surface of the r-ib 18 l will be determined byrevolving about the axis of rotation of the bearing .the same generatingelement used in -determining the thrust transmitting surface of theroller.

.It will be observed that regardless of Whether the generating elementforming the to 8 or is a straight line tangent to the vtheo- ,reticallycorrect surface, as in Figs. 9 and I0, no portion of a projection of thegenerating element is closer to the center 17 than is the portion of thegenerating element lying Within the limits ofthe bearing zone A-B of atheoretically correct spherical surface. Fig. 11 illustrates themodification of the truly spherical surface 7 of the roller ofV a thrustbearing to form the convex surface 7 having thc straight line elements7.' making an angle with the roller axis, or With the tapered surface ofthe roller, approximating thatl of the theoretically correct sphericalsurface. The surfaces 8 of the vperipheral pressure and guiding flanges8 may have the theoretically correct spherical curvature or may beformed with the same straight line elements .as'the roller ends.4 Ineither case, the straight line elements may be Worn down to-gth-etheoretically correct spherical 'isurface contact with comparativelylittle wear relatively to the life of the bearing.

By my improvements, the efficiency of the bearing is greatly increaseddue to reduced friction, the deterioration thereof by Wear is greatlydiminished, and the manufacturing voperations are simplified.

Having described my invention, I claim:

1. In an anti-friction bearing, the combination with races,'of rollersrespectively having a convex thrust-transmitting and guiding surfacecoincident at a plurality of points with a spherical contourgenerated'about a center coincident with the point of inter,- section ofthe axis of rotation of the bearing With the axes of rotation of therollers, and a thrust-resisting guiding surface conforming With-thethrust-transmitting surfaces of said rollers.

2 In an anti-friction bearing, the. combination with inner and outerraeeways en'- circling the axis of rotation of the bearing, of rollersdisposed between said raceways and each having a guiding surfacecoincident at a plurality of points with a spherical contour generatedabout a` center coincident With the intersection of the axes of rotationof the rollers with the axis of rotation 'of the bearing, and a guidingflange having a surface conforming and contacting With the guidingsurfaces of said rollers. t

3. In an anti-friction bearing, the combination with aceways, ofconoidal rollers disposed between said raceWays and tapering to a pointin the axis of rotation of the bearing, said rollers each having.a'convex outer end' having ai' curvature coincident with a sphericallsegmental contour generate/d about a center coincident with the pointof intersection ofthe axis of rotation of the bea-ring' with the apic'esofthe projected generating elements of the4 rollers, and a guidingmember 'having a surface conforming with the end bearing surfaces ofsaid rollers. Y

Il. In an anti-friction bearing, lthe combination With inner and outerconoidal race- Ways encircling the axis of rotation of the bearing andhaving apices meetin at a point in said axis, of tapered rollersdisposed between said raceways and having generating elements and axesof rotation converging to the meeting point of said apicesin the axis'of rotation of the bearing. v .Y

5. A roller bearing comprising races in combination with rollers pressednoutwardly by said races and eachvhaving a 'thrust trans- 30 mittingsurface coincident with or tangent to a spherical surface having itscenter at the `point of intersection of the axes ofv rotation of therollers Wi th the axis of-rota'tion of the bearing.

6. A roller bearing comprising races in" combination with rollers eaclrhaving a thrust transmitting surface generated by the rotation about theaxis of rotation of the roller" of a generating element coincident .witha tangent to a circle drawn about the point .of intersect-ion of theaxis of rotation ofthe roller with the axis of rotation of the bearing.

having a thrust transmitting surface formed b y a generating elementperpendicular to a 7. A roller bearing comprising rollers each hne drawnfrom the point of'i'ntersection of the axis of rotation of the rollerand the axis of rotation of the bearing to al point betweenthe axis andperiphery of theroller. A 8. In an anti-friction bearing, thecombination with inner and outer raceways encircling the axis ofrotation of the bearing, one of said raceWays being providedpwith athrust resisting guiding lflange, rollers having their larger endsadjacent to said flange, said rollers each having a 'thrust transmittingsurface adjacent to said flange and generated by the rotation about theroller axis of a straight line element substantially at right angles toa radius drawn from the point of intersection of the axes of the rollersWith the axis of the bearing to the zone of contact of the roller endand yfla-nge which would exist ifl said elements were curved on aspherical contour having its center at said point, the diameter of theroller being relatively small compared With the radius of such sphericalcontour, and the point of tangency of the generating element to suchspherical contour being such as to effect initial contact of the rollerend with the flange at separated points, said flange having a thrustresisting surface conforming to the contour of the thrust transmittingsurface of the end of the roller.

In testimony whereof I have hereunto 'set my hand this 29th day Vof May,1924.

' TRACY V. BUCKWALTER.

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of tapered

